Because of their thermal and oxidative stability and wide fluid ranges perfluoropolyalkylether fluids are being considered for use as engine oils, hydraulic fluids and greases and are actually used currently in space guidance systems and computer disc drives, among others. However, in oxidizing atmospheres and under conditions of boundary lubrications these compositions corrode metals/metal alloys and form volatile degradation products. Two kinds of additives were found to be effective in arresting the degradation process namely phospha-s-triazines described by K. L. Paciorek, R. H. Kratzer, J. Kaufman and T. I. Ito in U.S. Pat. No. 4,215,072 (1980), and by K. L. Paciorek, R. H. Kratzer, J. Kaufman and T. I. Ito in U.S. Pat. No. 4,166,071 (1979). The other type of additives are the phosphines described by C. E. Snyder, Jr. and C. Tamborski in U.S. Pat. No. 4,097,388 (1978) and C. T. Tamborski, C. E. Snyder, Jr. and J. B. Christian in U.S. Pat. No. 4,454,349 (1984). The additives disclosed in the present invention are more effective in arresting the degradation of perfluoropolyalkylether fluids in oxidizing atmospheres at elevated temperatures in the presence of metals/metal alloys than the currently used compounds. In addition these materials can function as rust inhibitors and provide lubricity enhancement. This invention pertains specifically to the synthesis of the perfluoroalkyl and perfluoroalkylether substituted aromatic phosphates, phosphonates and related compositions. These materials and the chemical intermediates employed in their preparation and disclosed herein are, to the best of our knowledge, new chemical compounds previously unknown.